Background: A pregnant woman's understanding and practice of healthy behaviors improves her health, achieves appropriate pregnancy outcomes, and enhances the mother and infant's quality of life. Aim: To evaluate the effectiveness of childbirth preparation classes on primigravida women`s health behavior. Subjects and method: Design: A quasi-experimental design was used. Setting: This study was conducted at DAR SAHET ELMAR`AA hospital in Port Said city. Subjects: Purposive sample of 66 primigravida women was included in this study. Tools of data collection: Two tools were used, A Health Behavior Inventory, and An observation checklist addressing intrapartum health behavior for women with normal labor. Results: The studied women demonstrated a significantly higher level of health behaviors during childbirth preparation (P < 0.001), with a reportedly high level (87.9%) of health behaviors regarding childbirth preparation in post-intervention than in the pre-intervention (13.6%). Conclusion: The childbirth educational class positively affects a primigravida woman's health behaviors regarding childbirth preparation. Recommendations: Designing and implementing childbirth preparation classes in various antenatal care settings during the third trimester of pregnancy, particularly for primigravidas.